La0.5Sr0.5CoO3 electrode technology for Pb(Zr,Ti)O-3 thin film nonvolatile memories

Oxide electrode technology is investigated for optimization of Pb(Zr,Ti)O-3 (PZT) thin film capacitor properties for high density nonvolatile memory applications. PZT thin film capacitors with RF sputter deposited La0.5Sr0.5CoO3 (LSCO) electrodes have been characterized with respect to the following parameters: initial dielectric hysteresis loop characteristics, fatigue performance, microstructure and imprint behavior. Our studies have determined that the fatigue of PZT capacitors with LSCO electrodes is less sensitive to B site cation ratio and underlying electrode stack technology than with RuO2 electrodes. Doping PZT thin films with Nb (PNZT) improves imprint behavior of LSCO/PZT/LSCO capacitors considerably. We have demonstrated that PNZT 4/30/70//LSCB capacitors thermally processed at either 550 degrees C or 675 degrees C have almost identical initial hysteresis properties and exhibit essentially no fatigue out to approximately 10(10) cycles.